Molecular baskets nab nerve agent simulants

Sequestering chemical warfare agents, pesticides, and other toxic compounds could be a slam dunk, thanks to molecular baskets designed by chemists at Ohio State University. Jovica D. Badjić and coworkers created a series of basket-shaped molecules that feature a flat aromatic base fused to three bicyclic rings to form a curved unit. Three phthalimides extend this curvature into a cavitand with threefold symmetry. The phthalimides carry amino acid substituents, placing three carboxylates at the rim of each basket (shown in dotted red rings). In water, these baskets form supramolecular complexes with organophosphonates that are similar in size and shape to certain nerve agents. When exposed to light with a wavelength of 300 nm, the baskets shed the carboxylates, trapping the nerve agent simulants inside (shown, bottom). Without the carboxylates, the complexes are no longer soluble in water; they precipitate for easy removal (J. Am. Chem. Soc. 2017, DOI: 10.1021/jacs.7b11960). “In principle, one can use the concept to remove any targeted compound from aqueous solution,” Badjić says, which could have applications in controlling chemical reactivity, cleaning the environment, or even removing toxic substances from biological systems.